Wind power installation

ABSTRACT

A wind power installation having external and/or internal redundancy derived by multiple, independent power generating systems arranged in parallel, but switchably interconnected to allow substantial continued operation in the event of a critical component failure.

RELATED APPLICATIONS

This application is a divisional application of application Ser. No.10/344,481 (now U.S. Pat. No. 6,946,750), filed Jun. 10, 2003, which isthe National Stage of International Application No. PCT/EP01/09239,filed on Aug. 10, 2001, both of which claim priority to German PatentApplication No. 100 40 273.9, filed on Aug. 14, 2000, the contents ofwhich are incorporated herein by reference.

BACKGROUND

The present invention concerns a wind power installation with preferablyat least rectifiers and two inverters.

Such a wind power installation is known from patent specification DE 19620 906.4. A disadvantage with that wind power installation however isthat, in the event of failure of the generator and/or the transformer,the wind power installation can no longer generate or deliver anyelectrical power. In the event of failure of a rectifier and/or aninverter it is still approximately half of the possible power yield thatis lost at any event, so that rapid repair is required in order to limitat least the economic damage to the operator of the installation due tothe energy yield which is lost.

That known wind power installation has two phase-displaced statorwindings which are arranged jointly on the same stator. The windingshowever are electrically insulated from each other and have a phaseangle of 30° relative to each other. In the event of failure of a statorwinding therefore half of the possible output power is still available.

In order to eliminate the fault and to repair the wind powerinstallation service personnel travel to the faulty wind powerinstallation and deal with the fault, either by a repair to the faultyor damaged components or, if repair is not possible, by replacing thedefective components by a replacement part.

It will be noted that rapid repair presupposes inter alia that the windpower installation is quick to reach and if necessary spare parts can bequickly brought to the installation.

If it can still be assumed that wind power installations which are setup on land can be quickly reached in that way, the situation is alreadymarkedly different in relation to off-shore installations, that is tosay wind power installations which are set up off the coast and thus atsea. On the one hand a suitable transport means must be available, withwhich possibly even large-volume and/or heavy spare parts can betransported and handled, while on the other hand the weather and thestate of the sea must allow the installation to be safely reached, evenwith the loaded spare parts. Even if it is possible to reach theinstallation however, it is in no way certain in that respect that thesea swell and the weather will permit immediate repair.

It will be seen therefore that, if the swell is high or if the weatheris bad, such as for example if there is a storm, it is definitely notpossible to reach or repair off-shore installations, for a relativelylong period of time, and therefore the off-shore installations cannotgenerate or deliver power for a prolonged period of time.

A further disadvantage with the previously known wind powerinstallation, as also all others, is that the concept on which that windpower installation is based means that the dimensions and the inherentweight of the individual components become greater, with an increasinggenerator output.

SUMMARY OF THE INVENTION

In order to limit the damage due to the failure of components of a windpower installation and to allow the use of standard components, inaccordance with the invention there is proposed a wind powerinstallation of the kind set forth in the opening part of thisspecification, having at least two stators each with at least one statorwinding, and at least two transformers. Advantageous developments aredescribed in the further claims.

Accordingly the wind power installation according to the invention hasat least two stators, two rectifiers, two inverters and twotransformers. They respectively form, starting from the stator, aspecific and complete system for the production of electrical energy,for conversion into for example a sinusoidal ac voltage and for feedinginto an ac voltage network.

A preferred embodiment of the invention has four stators which arearranged in the form of a circular ring and which are in the shape ofcircular ring segments and which each have at least one winding of theirown. As a result, the dimensions and the inherent weight of each statorremain in a range in which transportation and handling of the stator canbe implemented with the usual available aids.

In a preferred development of the wind power installation according tothe invention each stator has two three-phase current windings which areelectrically separated from each other and which are displaced relativeto each other at a phase angle of 30°. By virtue of that measure a partof the exciter current for the rotor can be produced in the statorwinding.

In a particularly preferred development of the invention a rectifier, aninverter and a transformer are associated with each stator. Thatarrangement affords four separate power production systems, apart fromthe common rotor. Accordingly each system produces a quarter of thepossible total output power. It follows therefrom that, in the event offailure of a component, only one system fails, and therewith just aquarter of the instantaneous overall output power. Accordingly thereforethree quarters of the output power are still available.

If a total output power of 6 MW is considered for a wind powerinstallation, each system accordingly involves an output power of 1.5MW. That output power makes it possible to use standard components whichare already available and produced in large numbers nowadays, asrectifiers, inverters and transformers. As a result the probability offailure is markedly reduced due to the use of technically maturedcomponents which are produced in large numbers, and that in turncontributes to a permanently high level of yield from a wind powerinstallation according to the invention.

In accordance with a preferred embodiment of the invention a rectifier,an inverter and a transformer are associated with each stator winding. Apower production system is accordingly formed from a stator winding, arectifier, an inverter and a transformer. That design configurationmeans that each of the systems is only involved with an eighth of theinstantaneously available output power. Therefore, in the event offailure of a component and thus a system, only an eighth of theavailable power is no longer available, but seven eighths are stillavailable.

In addition this concept in turn permits production of an even highernumber of standard components and thus a reduction in cost. In additiontransportation and handling means, procedures and methods are availablefor those components and have been tried out in many situations.

In a particularly preferred embodiment of the invention the rectifiers,the inverters and the transformers are designed to be over-dimensioned,preferably by about 20%, and provided between each two rectifiers,between each two inverters and between each two transformers are switchdevices which in the event of failure of a component permit it to beby-passed.

Due to the over-dimensioning the remaining components can at leasttemporarily take over the function of the failed component without thatcausing an overloading to occur. If therefore, for example, a rectifierfails the switch devices between the failed rectifier and one or moreadjacent operational rectifiers can be actuated. In that way theoperational rectifiers are acted upon with a correspondingly higheroutput power and also rectify the ac voltage from the system with thefailed rectifier.

In a particularly preferred feature control of the switch devices iseffected having regard to the output power to be switched, so that onlyone switch device switches when the level of output power is low. If theoutput power to be switched is higher a plurality of switch devices areactuated in order thereby to distribute the loading to a plurality ofcomponents and to avoid overloading.

In a particularly preferred development of the invention switch devicesare provided in the feed line and/or the out line of each component withthe exception of the stators. By actuation of the corresponding switchdevices it is possible to reliably avoid any reaction on the part of thecomponent to be by-passed if that component is completely disconnectedby the switch devices.

In an alternative embodiment of the invention the feed lines and outlines of the individual components are connected in parallel. That saveson switch devices, in the event of failure of a component all the othercomponents are always automatically operated and the control system issimplified as it is only the failed component that has to bedisconnected by switch devices in the feed lines and/or out lines.

The redundancy of the individual components is referred to as ‘externalredundancy’ and identifies the possibility, in the event of failure of acomponent, of causing the function thereof to be taken over by aredundantly present, other component. In the event of failure of arectifier therefore other rectifiers take over the function, in theevent of failure of an inverter other inverters take over the functionand in the event of failure of a transformer other transformers takeover the function.

In comparison there is also internal redundancy. That denotesconstructing a component with a plurality of modules which are presentredundantly with each other and which relative to the exterior form acomponent such as for example an inverter. Therefore in the event offailure of one of a plurality of modules of an inverter that invertercan definitely still remain operational as the remaining modules of theinverter can still continue to implement the function involved.

Accordingly a stator with two windings also has internal redundancy as,in the event of failure of one winding, the second winding is stillavailable for generating power so that the stator can still deliver halfof the possible output power.

Accordingly the wind power installation according to the invention candeliver all of the instantaneously available output power even in theevent of failure of individual components or modules, with the exceptionof a stator or a stator winding.

Further advantageous developments of the invention are described in theappending claims.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is described in greater detailhereinafter by means of an example. In the drawings:

FIG. 1 shows a simplified view of a system according to the invention,

FIG. 2 shows a view, supplemented by switch devices, of the systemillustrated in FIG. 1,

FIG. 3 shows an example of two stator windings displaced through 30°,with a rectifier connected on the output side thereof,

FIG. 4 shows an example of an inverter according to the invention,

FIG. 5 shows an example of redundantly provided transformers havingswitch devices,

FIG. 6 shows a second embodiment of the present invention,

FIG. 7 shows an example of redundantly provided transformers in thesecond embodiment of the present invention, and

FIG. 8 shows a known system.

DETAILED DESCRIPTION

FIG. 8 shows a known electrical system of a wind power installation.That electrical system includes a generator which in this example is inthe form of a ring generator. The ring generator has a rotor (not shown)and two stator windings 111, 112 which are electrically insulated fromeach other and which are phase-displaced through 30° relative to eachother.

The stator windings 111, 112 are each connected to the input of arespective rectifier 14 specific thereto. The output of each rectifier14 is connected to an input of a respective inverter 16. The outputs ofthe inverters 16 are connected in parallel to a transformer 18.

Just the failure of the transformer 18 inevitably results in economictotal failure of the wind power installation as it is not possible forany further energy to be delivered. As a result the operator suffersfrom considerable loss, depending on the respective duration of thefailure.

The failure of a stator winding 111, 112, a rectifier 14 and/or aninverter 16 also in any case results in a loss of half the possibleenergy yield and thus also results in considerable economic damage.

FIG. 1 shows a simplified example of a wind power installation accordingto the invention. Most components are redundantly present in this windpower installation. Such redundancy concerns parts of the generator,namely stators 121, 122, 123, 124, rectifiers 141, 142, 143, 144,inverters 161, 162, 163, 164 and transformers 181, 182, 183, 184.

That redundancy which arises out of a parallel arrangement of theredundant components is external redundancy. In addition with somecomponents there is also internal redundancy which arises out of theinternal structure of the component being made up of a plurality ofsimilar modules connected in parallel. That internal redundancy is to befound for example in the case of the inverters which are described ingreater detail with reference to FIG. 4.

For the purposes of the description hereinafter, in a similar manner tothe foregoing way of considering matters, each element 121, 122, 123,124 which is in the form of a segment of a circular ring and which hasat least one winding in which a voltage is induced by the rotating rotorR is referred to as a stator even if there are four elements 121, 122,123, 124 which are in the form of a segment of a circular ring and theyare arranged in such a way that together they approximately form theshape of a one-piece stator of a ring generator, as in the case of thepresent embodiment.

The stators 121, 122, 123, 124 which are arranged in the form of acircular ring and which are in the shape of segments of a circular ringtogether approximately form a circular ring in which the rotor R of thegenerator is centrally rotated by the wind power installation rotor hub(not shown) with the rotor blades fixed thereto. As the individualstators 121, 122, 123, 124 are separated from each other not onlymechanically but also electrically, voltages are correspondingly inducedin the windings on the stators 121, 122, 123, 124.

Those voltages are ac voltages which are passed through conductors 201,202, 203, 204 to rectifiers 141, 142; 143, 144. Those conductors 201,202, 203, 204 can be for example aluminum bars with a cross-sectionalarea of 4,000 mm². In that respect a separate rectifier is associatedwith each stator 121, 122, 123, 124. It follows therefrom that, even ifa rectifier fails, only a quarter of the possible energy yield is nolonger available. Accordingly three quarters of the possible outputpower is still available.

Connected on the output side of each rectifier 141, 142, 143, 144 is aninverter 161, 162, 163, 164 and also connected thereto by a conductor205, 206, 207, 208. Those conductors 205, 206, 207, 208 can also bealuminum bars of a cross-sectional area of 4,000 mm².

Connected on the output side of each inverter 161, 162, 163, 164 thereis again a transformer 181, 182, 183, 184 by way of which the ac voltagegenerated by the inverters 161, 162, 163, 164 is stepped up to forexample 20 kV and fed for example into a medium-voltage network.

In that way, starting from the stator windings in which the voltage isinduced by the generator rotor, there are mutually independent systems101, 102, 103, 104 with rectifiers 141, 142, 143, 144, inverters 161,162, 163, 164 and transformers 181, 182, 183, 184 so that a failure of acomponent prevents at most the provision of a quarter of the possibleoutput power.

FIG. 2 is expanded in comparison with FIG. 1 by switch devices 130, 131,132, 133, 134, 135, 136, 146, 147, 148, 149, 150, 151, 152, 153, 154,155, 156, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 186,187, 188, 189. These are referred to hereinafter in their totality byreference numerals 130–136, 146–156, 166–176 and 186–189. In order toretain clarity of the Figure, the references for the conductors betweenthe stators 121, 122, 123, 124, the rectifiers 141, 142, 143, 144 andthe inverters 161, 162, 163, 164 and the markings of the systems 101,102, 103, 104 have been omitted here.

In normal operation the switch devices 130, 131, 132, 150, 151, 152,170, 171, 172 between the feed lines of the individual components areopen and the switch devices 133, 134, 135, 136, 146, 147, 148, 149, 153,154, 155, 156, 166, 167, 168, 169, 173, 174, 175, 176, 186, 187, 188,189 in the feed lines and outlines in series with the respectivecomponents are closed in normal operation so that each system 101, 102,103, 104 (FIG. 1) operates separately from the others.

The switch devices 130–136, 146–156, 166–176, 186–189 are nowcontrollable in such a way that they make connections between individualcomponents of at least two systems 101, 102, 103, 104. Those connectionsare made in such a way that the feed lines of two similar components arealways connected parallel by each switch device 130, 131, 132, 150, 151,152, 170, 171, 172.

For example the feed lines of the rectifiers 141 and 142 are connectedin parallel by actuation of the switch device 130, the inputs of theinverters 161 and 162 by actuation of the switch device 150 and theinputs of the inverters 162 and 163 by actuation of the switch device151. It will be appreciated that combinations in that respect are alsopossible.

In order to avoid a reaction of failed or faulty components on thosewhich are still operational, provided in the feed lines and out lines ofthe individual components are switch devices 133, 146; 134, 147; 135,148; 136, 149; 153, 166; 154, 167; 155, 168; 156, 169; 173, 186; 174,187; 175, 188; 176, 189 which preferably disconnect the respectivecomponent, with all lines.

In the case of a fault in a component therefore that component isby-passed by suitable actuation of the switch devices 130–136, 146–156,166–176 and 186–189 so that, in spite of the fault, the wind powerinstallation still delivers the major part of the power generated oreven all the power generated.

In order to prevent overloading of the intact components which haveremained, and thus to prevent premature failure thereof, thosecomponents are preferably over-dimensioned by about 20% so that evenwhen those remaining components are loaded with the output power of afailed component, that does not cause any overloading.

The switch devices 130–136, 146–156, 166–176 and 186–189 are in thiscase so arranged and are controlled in such a manner that admittedly itis possible to by-pass a component such as for example a rectifier 141,142, 143, 144 or an inverter 161, 162, 163, 164, but it is not possibleto skip over a function implemented by such components.

In the event of a failure for example of the inverter 162 the normallyopen switch devices 150, 151, 152 can be closed in order to connect therest of the inverters 161, 163, 164 to the feed line of the inverter162. At the same time the normally closed switch devices 154, 167 areactuated and thereby opened in order to disconnect the failed inverter162.

Finally the normally opened switch devices 170, 171, 172 can be actuatedand thus closed so that the three inverters 161, 163, 164 again act onall four transformers 181, 182, 183, 184.

In that way the failed inverter 162 is by-passed and, in spite of thefailure of the inverter 162, the wind power installation can deliver allthe available power produced.

FIG. 3 shows a particularly preferred embodiment of the stator windingsand the rectifier connected downstream thereof, using the example of thesystem 101. The stator windings 1211 and 1212 with thedownstream-connected rectifier 141 are described here. This arrangementwhich is described by way of example is identical to that of the otherredundant systems 102, 103, 104.

The stator 121 which is not shown in FIG. 3 carries two stator windings1211, 1212 which are displaced through 30° relative to each other. Bothstator windings 1211, 1212 are in the form of three-phase currentwindings and thus each has three phase windings 1213, 1214, 1215 and1216, 1217, 1218. That total of six phase windings 1213, 1214, 1215,1216, 1217, 1218 are connected to a six-phase rectifier 141.

The phase angle between the individual phases 1213, 1214, 1215 and 1216,1217, 1218 of a winding is 120°. If a rotor (not shown) is assumed to berotating in the clockwise direction, then the phases of the voltagesinduced in the winding 1211 trail the phases of the voltages induced inthe winding 1212, by 30°. As the phases of a winding are displacedrelative to each other through 120°, for example the voltage in thephase 1214 in the winding 1211 trails the voltage in the phase 1217 inthe winding 1212 by 30°, but leads the phase 1218 in the winding 1212 by90°. In that way a part of the exciter power required for the phase 1218can be produced in the phase 1214.

As both three-phase current windings 1211, 1212 are arranged on a stator121, an internal redundancy is already embodied here so that, uponfailure of a winding 1211, 1212, the other winding 1212, 1211 can alwaysstill produce output power which is then passed to the rectifier 141.

A preferred embodiment of an inverter 161, 162, 163, 164 according tothe invention is shown in FIG. 4. The provision of a plurality ofinverters 161, 162, 163, 164 provides for external redundancy.

Taking the example of the inverter 161 whose structure is the same asthe structure of the other inverters 162, 163, 164, FIG. 4 shows that itis made of three modules 1611, 1612, 1613 which embody internalresistance. The structure of the individual modules 1611, 1612, 1613 isthe same with each other; in the present case they have IGBTs asswitching elements which by suitable actuation produce the ac voltagefrom the applied dc voltage +Ud and −Ud. In addition the structure andthe mode of operation of such modules are known from the state of theart and therefore a detailed description of the mode of operation willnot be included here.

Each module 1611, 1612, 1613 produces a three-phase ac voltage from theapplied dc voltage and can be connected by way of switches 1614, 1615,1616 to the outputs L1, L2, L3 of the inverter 161.

The number of modules in an inverter 161, 162, 163, 164 however is notlimited to three. It is equally possible to select a different number ofmodules 1611, 1612, 1613 and preferably a larger number in order to alsoembody a desired internal redundancy, besides the external redundancy.

The number of modules again makes it possible to implementover-dimensioning in order in this case also to obviate overloading andthus premature failure in the event of a fault in another inverter 161,162, 163, 164.

FIG. 5 shows a redundant arrangement of transformers 181, 182, 183, 184which are preferably in the form of three-phase current transformers andwhich at the primary side are acted upon for example in each case with3×400 V from the inverters 161, 162, 163, 164 and which on the secondaryside deliver for example to a medium-voltage network an ac voltage whichis transformed to for example 3×20 kV.

Those transformers 181, 182, 183, 184 are preferably alsoover-dimensioned in order to be able to operate reliably even afterbeing subjected to the application of additional output power from afaulty or failed transformer 181, 182, 183, 184.

FIG. 5 once again shows the switch devices 170, 171, 172, 173, 174, 175,176, 186, 187, 188, 189 which permit by-passing of a failed transformer181, 182, 183, 184. In that case switch devices 173, 186; 174, 187; 175,188; 176, 189 permit the primary and secondary windings of the failedtransformers 181, 182, 183, 184 to be switched off in order in that wayto avoid an impedance shift due to the parallel connection of theprimary windings and/or the secondary windings of the transformers 181,182, 183, 184 upon closure of the switch devices 170, 171, 172.

For that purpose the switch devices 173, 174, 175, 176 arranged at theprimary side and the switch devices 186, 187, 188, 189 arranged at thesecondary side are so designed that they galvanically separate allterminals of the corresponding transformer winding. In that respectcontrol is preferably effected in such a way that both switch devices173, 186; 174, 187; 175, 188; 176, 189 at a transformer 181, 182, 183,184, that is to say for example the primary-side switch device 174 andthe secondary-side switch device 187 at the transformer 182, are alwayssimultaneously actuated in order reliably to disconnect the transformer182.

FIG. 6 shows a second embodiment of the present invention. Thisembodiment corresponds in large parts thereof to the embodiment shown inFIG. 2 and differs therefrom by virtue of the saving on the switchdevices 130, 131, 132, 150, 151, 152, 170, 171, 172 in FIG. 2 betweeneach two components, so that the similar components of the individualsystems 101, 102, 103, 104 in FIG. 1 are connected in parallel andaccordingly in normal operation are all acted upon by approximately aquarter of the output power produced.

In a manner corresponding to the arrangement in the first embodiment theswitch devices 133, 134, 135, 136, 146, 147, 148, 149, 153, 154, 155,156, 166, 167, 168, 169, 173, 174, 175, 176, 186, 187, 188, 189 areclosed in normal operation so that all systems 101, 102, 103, 104 areoperating.

If now a fault occurs at a component that component is disconnected byopening of the switch devices 133, 146; 134, 147; 135, 148; 136, 149;153, 166; 154, 167; 155, 168; 156, 169; 173, 186; 174, 187; 175, 188;176, 189 arranged in the feed line and the out line of the component inquestion, and the other components in the other systems 101, 102, 103,104 (FIG. 1) are automatically acted upon with a higher level of outputpower.

This can also be clearly seen once again from FIG. 7 in which thetransformers 181, 182, 183, 184 are connected in parallel by thenormally closed switch devices 173, 174, 175, 176, 186, 187, 188, 189.If now a transformer 181, 182, 183, 184 is found to be defective orfaulty the associated switch devices 173, 186; 174, 187; 175, 188; 176,189 are actuated (opened) and the transformer in question isdisconnected while the other transformers 181, 182, 183, 184 arerespectively acted upon with a higher level of output power and the windpower installation still delivers all the energy produced.

Preferably the rectifiers 141, 142, 143, 144 shown by way of example inFIG. 1 are disposed in the machine housing, that is to say in the pod ofthe wind power installation. The inverters 161, 162, 163, 164 arepreferably disposed in the base region of the pylon of a wind powerinstallation and the inverters and the rectifiers are connected togetherby way of direct current bus bars 205, 206, 207, 208. The transformerfor feeding the electrical output power produced into the network, inthe case of an off-shore wind power installation, can also be disposedin the lowermost base region of a pylon of the wind power installation,that is to say below the water line.

1. A wind power installation having a power generation redundancysystem, the wind power installation comprising: a plurality of powergenerating systems, including: a first power generating system having aplurality of components including: a stator; a feed line configurationto connect the stator with a power transmission line, wherein the feedline configuration includes a rectifier, an inverter, and a transformer;and a second power generating system having a plurality of componentsincluding: a stator; a feed line configuration to connect the stator ofthe second power generating system with the power transmission line,wherein the feed line configuration of the second power generatingsystem includes a rectifier, an inverter, and a transformer; and whereinthe plurality of power generating systems are electricallycross-connected at selected points to by-pass a failure of one or moreof the rectifiers, the inverters, and/or the transformers.
 2. The windpower installation of claim 1 wherein the rectifier in the feed lineconfiguration of the first power generating system is over-dimensioned,relative to a nominal operating load, to power load share in the eventof a component failure.
 3. The wind power installation of claim 1wherein the inverter in the feed line configuration of the first powergenerating system is over-dimensioned, relative to a nominal operatingload, to power load share in the event of a component failure.
 4. Thewind power installation of claim 1 wherein the transformer in the feedline configuration of the first power generating system isover-dimensioned, relative to a nominal operating load, to power loadshare in the event of a component failure.
 5. The wind powerinstallation of claim 1 wherein the stator of each power generatingsystem is an independent segment of a circular ring that is disposedaround a rotatably mounted rotor wherein the stators of the plurality ofpower generating systems, in combination, substantially form at least aportion of the circular ring.
 6. The wind power installation of claim 1wherein the plurality of power generating systems further include: athird power generating system having a stator and a feed lineconfiguration, wherein an output of the stator of the third powergenerating system is electrically connected to an input of the feed lineconfiguration of the third power generating system, is and wherein thefeed line configuration of the third power generating system includes arectifier, an inverter and a transformer; a fourth power generatingsystem having a stator and a feed line configuration, wherein an outputof the stator of the fourth power generating system is connected to aninput of the feed line configuration of the fourth power generatingsystem, and wherein the feed line configuration of the fourth powergenerating system includes a rectifier, an inverter and a transformer;and wherein the transformer of the feed line of configuration of eachpower generating system, in combination, provide the output power of thewind power installation.
 7. The wind power installation of claim 6wherein the stator of each power generating system is shaped in the formof a segment of a circular ring, and wherein the stators, incombination, substantially form the circular ring that is disposedaround a rotatably mounted rotor.
 8. The wind power installation ofclaim 6 further including a switch network to electricallycross-connect, at selected points, one or more of the rectifiers, theinverters, and/or the transformers of the feed line configurations ofthe power generating systems.
 9. The wind power installation of claim 8wherein the switch network includes a plurality of normally openswitches and a plurality of normally closed by-pass switch pairs. 10.The wind power installation of claim 9 wherein one or more of theplurality of normally open switches and one or more of the plurality ofnormally closed by-pass switch pairs responsively switch to by-pass oneor more components of the feed line configuration of at least one of theplurality of power generating systems.
 11. The wind power installationof claim 1 further including a switch network to electricallycross-connect, at selected points, one or more of the rectifiers, theinverters, and/or the transformers.
 12. The wind power installation ofclaim 11 wherein the switch network includes a plurality of normallyopen switches and a plurality of normally closed by-pass switch pairs.13. The wind power installation of claim 12 wherein one or more of theplurality of normally open switches and one or more of the plurality ofnormally closed by-pass switch pairs responsively switch to by-pass oneor more components of the feed line configuration of at least one of theplurality of power generating systems.
 14. The wind power installationof claim 1 wherein the stator of each power generating system comprisestwo windings.
 15. The wind power installation of claim 14 wherein thetwo windings are electrically displaced relative to each other through30°.
 16. The wind power installation of claim 14 wherein the windingscomprise a three-phase current winding.
 17. The wind power installationof claim 1 wherein the rectifier in the feed line configuration of thefirst power generating system and the rectifier in the feed lineconfiguration of the second power generating system areover-dimensioned, relative to a nominal operating load, to power loadshare in the event of a component failure.
 18. The wind powerinstallation of claim 1 wherein the inverter in the feed lineconfiguration of the first power generating system and the inverter inthe feed line configuration of the second power generating system areover-dimensioned, relative to a nominal operating load, to power loadshare in the event of a component failure.
 19. The wind powerinstallation of claim 1 wherein the transformer in the feed lineconfiguration of the first power generating system and the transformerin the feed line configuration of the second power generating system areover-dimensioned, relative to a nominal operating load, to power loadshare in the event of a component failure.
 20. The wind powerinstallation of claim 1 wherein the rectifier, inverter and transformerin the feed line configuration of the first power generating system areover-dimensioned, relative to a nominal operating load, to power loadshare in the event of a component failure.